On Thursday, the circuit -breakers forced the mainland’s stock markets to shut down early for the second day this week.

The CSI 300 Index plunged 7.2% Thursday, triggering an automatic shutdown within 30 minutes of the open. The circuit breakers, which went into effect on Monday, stop trading on all exchanges for 15 minutes after a 5% drop in the CSI 300, and shut the market down for the rest of the day after a 7% decline. The Shanghai Stock Exchange Composite Index also fell 7% to 3,1245 and the Shenzhen Stock Exchange Composite Index sank 8.2% to 1,958 . The circuit breakers are triggered only by moves on the CSI 300.

Many analysts say the circuit-breakers exacerbate market losses as investors scramble to exit positions before getting locked in by a full market halt.

The China Securities Regulatory Commission announced the suspension on its official microblog account on Thursday night, reported Bloomberg. The decision came hours after CSRC officials held an emergency meeting to discuss conditions on the nation’s tumbling stock market, according to a person familiar with the discussions who asked not to be named because he wasn’t authorized to speak publicly.

Unlike Monday, when the market fell on reports that factory output had contracted for the 10th straight month, Thursday’s market decline was sparked by a sharp decline in the value of the yuan.

“They are changing the rules all the time now,” Maarten-Jan Bakkum, a senior emerging-markets strategist at NN Investment Partners in The Hague told Bloomberg . “The risks seem to have increased.”

The trading circuit breakers themselves aren’t the problem. They seem to work well in other major markets. However, the distance between the two points for a halt look very tight compared to other markets.

In the US, trading is halted temporarily after declines of 7% and 13% in the Standard & Poor’s 500 Index. The market has to plunge 20% for the market to be suspended for the rest of the day.

Hugh Young, a managing director at Aberdeen Asset Management, told Bloomberg that China’s efforts to intervene in the stock market are counterproductive.

“Often, the more measures the government takes, the more it encourages people to go against it,” Young said. “They should regulate the market to make sure rules are clear and people abide by the rules. They shouldn’t worry as stock prices go up or down.”